5. Multiple Iterative Seeding of Surface Plasmon Enhanced Cobalt-Iron Oxide Nanokernels for Cancer Theranostics

Cancer is the second leading disease which causes major mortality and morbidity worldwide [1]. In cancer therapy, it is crucial to increase the drug specificity and drug efficacy to minimize or completely eradicate significant side effects on patients [2]. Cancer nanotherapeutics overcome many serious drawbacks of chemotherapy such as nonspecific targeting, lower efficacy, insolubility of drug moieties in water, and oral bioavailability [3]. Accordingly, Superparamagnetic Iron Oxide Nanoparticles (SPIONs) are exploited as an important nanomaterial for cancer detection as well as therapeutics [4]. Such magnetic nanoparticles (NPs) gained its momentum because of their single-domain ordering along with their large surface-to-volume ratio (providing large surface area for attachment of biological entities). Hence, this property makes them a suitable candidate as a contrast agent, drug-carrying cargo, and hyperthermal agent [5]. The doping of SPIONs with cobalt ions further enhances their magnetic property, thus forming CoFe₂O₄ nanokernels (Nks). These spinel ferrite Nks possess ca. 20–30 times higher magneto-crystalline anisotropy as compared to SPIONs; this increases the performance of materials for biomedical applications [6–8]. Specifically, these Nks are mostly used in biomedicine than any other spinel structure because of their enhanced magnetic property and large anisotropy [9]. The increased superparamagnetism makes them an efficient system for theranostics [10–12].